US stock trading will be closed on Monday and possibly Tuesday in response to Hurricane Sandy, NYSE Euronext said late on Sunday.

NYSE Euronext, which runs the New York Stock Exchange, had previously said that electronic trading would remain open and that only the exchange’s trading floor would close.

In a statement, the company said that “the dangerous conditions developing as a result of Hurricane Sandy will make it extremely difficult to ensure the safety of our people and communities, and safety must be our first priority.”